Java程序设计之算出一年第多少天

package year;

import java.util.Scanner;

public class year {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        year y = new year();
        y.fun();
    }
    
    public void fun(){
        String str = shuru();
        int year = Integer.parseInt(str.split(" ")[0]);
        int month = Integer.parseInt(str.split(" ")[1]);
        int day = Integer.parseInt(str.split(" ")[2]);
        jisuan(year,month,day);
    }
    
    private String shuru(){
        System.out.print("输入年月日中间以空格间隔：");
        Scanner s = new Scanner(System.in);
        return s.nextLine();
    }
    
    private void jisuan(int year, int month,int day){
        int i = 0;
        int j = 0;
        //是闰年
        if(year%400 == 0||year%4==0&&year%100!=0){
            switch(month){
            case 12: i+=31;
            case 11: i+=30;
            case 10: i+=31;
            case 9: i+=30;
            case 8: i+=31;
            case 7: i+=31;
            case 6: i+=30;
            case 5: i+=31;
            case 4: i+=30;
            case 3: i+=31;
            case 2: i+=28;
            case 1: i+=31;
            }
            if(month == 1||month == 3||month == 5||month == 7||month == 8||month == 10||month == 12){
                j = 31 - day;
                System.out.println(i-j);
            }else if(month == 2){
                j = 28 - day;
                System.out.println(i-j);
            }else{
                j = 30 - day;
                System.out.println(i - j);
            }
        }else{
            switch(month){
            case 12: i+=31;
            case 11: i+=30;
            case 10: i+=31;
            case 9: i+=30;
            case 8: i+=31;
            case 7: i+=31;
            case 6: i+=30;
            case 5: i+=31;
            case 4: i+=30;
            case 3: i+=31;
            case 2: i+=29;
            case 1: i+=31;
            }
            if(month == 1||month == 3||month == 5||month == 7||month == 8||month == 10||month == 12){
                j = 31 - day;
                System.out.println(i-j);
            }else if(month == 2){
                j = 28 - day;
                System.out.println(i-j);
            }else{
                j = 30 - day;
                System.out.println(i - j);
            }
        }
    }
}